Flame igniter



United States ,Patent O FLAME IGNITER Franz Joseph Marie Raskin, Montreal, Quebec, Canada Application March 1, 1955, Serial No. 491,272

1 claim. (cl. 15s-115) The present invention relates to a flame igniter and more particularly to a gas torch for igniting burners using oil, gas, or pulverized'coal as 'fuels tov be burned in suspension.

A gas igniter torch must meet the following requirements:

(1) It should require no adjustment duringoperation. (2) It must produce a clean ystable flame which is not liable to leave the end of the torch. If.v it leaves the end of the torch, it can not only; go out but also the flame may not be in the'properlocation to-ignite the main -fuel SPlaY. Y

(3) It must operate uniformly whether the air pressure conditions at the ltorch location are below or above normal atmospheric pressure; 'j n, "fr n N (4) It must be suitable for all fuel gases.

(5) It must be designedfto be capable of being lit automatically.

(6) With an automatically litil arrangement ythe electrode and electrode insulator must be both protected from the high temperature of the torch and ythe main burner ames, otherwise:

(a) The electrode' will overheat and bend, and thereby either short-circuit or increase the spark gap to a point where the igniting spark would not be produced; `it sometimes burns out entirely such as happens in some equipment now on the market.

(b) The porcelain insulator will overheat and thereby lose its insulating properties, and create a short circuit.

Accordingly, the general object of the present invention consists in the provision of a flame igniter which fulfills the above mentioned requirements.

A more specific object of the present invention is the provision of a flame igniter in which the electrode is protected against the radiant heat from the oil burner flame to thereby prevent its overheating and bending.

Another important object of the present invention is the provision of a gas torch having an improved nozzle so designed as to produce a clean and stable flame which will not leave the end of the torch and be extinguished.

Yet another important object of the present invention is the provision of a gas torch which is lighted automatically and which burns efficiently irrespective of the differences of the pressures prevailing inside and outside the oil burning chamber.

Still another important object of the present invention is the provision of a gas torch which, once set, will not require further adjustment.

Yet another important object of the present invention is the provision of a gas torch which may be easily adjusted to burn different types of gaseous fuel and which is mounted in such a manner that its position can be changed relatively to the oil burner nozzle.

The foregoing and other important objects of the present invention will become more apparent during the following disclosure and by referring to the drawings in which:

y 2,880,792 Patented' Apr'. 7, 1959 'Figure l is a longitudinal section of the gas torch according to the invention;

Figure 2 is a cross-section taken along line 2-2 of Figure 1; and Y Figure 3 is a cross-section taken along line 3-3 of Figure 1.

Referring -now more particularly to the drawings in which like reference characters indicate like elements throughout, the gas torch ismounted in a ball bracket 33, shown in Figure l.y

' The construction of the gas vtorch is clearly shown in Figures l1 to 3. It comprises a gas chamber 36 defined by .a first tube 37 which is inserted in the ball bracket 33. A

spark plug holder 38 is threaded on the rear end of the tube 37 and carries ra spark plug 39. The spark plug holder 38 is provided with a side opening to which is secured a nipple 40 itself connected to the pressure reducing-valve 28.- The valve 28 is provided with a partition 42 having a threaded opening for receiving a bored screw rplug 43 which may beremoved through a side opening 41 made in thevalve 28 and normally closed by a screw plug `44. A screw plug 43 having a bore diameter suited to the type of fuel'gas used and to the gas pressure in the main supply line, will bel inserted in the valve 28.

The spark `plug 39 vis connected to an electrode 45 by means of an electrode connector 46.

The electrode 45- consists in a metal rod which projects outwardly from the forward end 47 of the tube 37 and is bent at right angles to form an electrode tip 48.

The electrode 45 is partly surrounded by a porcelain insulatingisleeve 49 which also projects outwardly from theforward end of the tube 37.

An annular flange 50 is secured to the forward end 47 of th'e tube 37 to definean annular passage. or orifice 51 between the inner edge of the flange 50 and the porcelain sleeve `49. The electrode 45 and the sleeve 49 are centered with respect of the orifice 51 by means of centering `set screws 52threadedly engaging the forward end 47 of the tube 37 and abuttingthe spider 53 surrounding the porcelain sleeve 49.

A mixing or second tube 54 is in telescopic engagement over the first tubel 37 and is maintained thereon by means of two groups of locating set screws 55. y p

The mixingV tube54 is provided at its rear portion with equally spacedv air admission slots 56, preferably four in number.

The effective opening of the air slots 56 is adjusted, according to the type and pressure of the fuel gas, by longitudinal movement of mixing tube 54 on tube 37. Also the spark gap between the electrode tip 48 and the inner face of mixing tube 54 may be adjusted by varying the angle of tube 54 relatively to tube 37 by means of set screws S5. v

The forward end of the mixing tube 54 forms a nozzle 57 which consists in a cylindrical flange 58 and an inwardly extending conical flange 59.

The flanges 57 and 59 define a recess 60 of triangular cross-section. The conical flange 59 is provided with a plurality of small orifices 61 and defines the main nozzle orifice 62.

The gas torch 23 is so disposed that the same air pressure exists at the air admission slots 56 and at the nozzle 57 of the tube 54.

Gas pressure within the gas chamber 36, defined by tube 37, is maintained substantially uniform due to the presence of the pressure reducing plug 43 whereby variations in the gas supply pressure are smoothed out.

Also the variations in the pressure caused by the normal fluctuation in the normal supply pressure will not affect the torch operation because, due to the construction of the nozzle, stable operation is possible within limits far greater than results from normal variations in the main gas supply. pressure. The gas discharges within the mixing tube 54 through the annular orifice 51 and is mixed with air drawn through slots 56 into the mixing tube 54 through the venturi effect of the gas issuing from the orifice 51. Part of the air gas mixture passes into the annular recess 60 through holes 61 whereby the gas air mixture velocity is reduced to a point well below the velocity of flame propagation of the mixture, such that the flame cannot leave the annular recess 60 and the resulting annular flame helps to positively insure that the ma'in ame issuing from the nozzle orifice 62 cannot leave the end of the torch.

The sparks created at the electrode tip 48 ignite only a few particleswhich are immediately discharged through the orifices 61 and 62 to ignitel the gas mixture outside the tube 54. The velocity ofV the mixture issuing from the nozzle orifice 62 is well above the-velocity of flame propagation of the mixture whereby it is impossible for the flame to enter the mixing tube 54. Moreover, `there is not enough air in the tube 54 to maintain a velocity of flame propagation approaching the velocity of the mixture in tube 54.

A stable clean flame is produced because the proper amount of primary air is admitted into the tube 54 through air inlets 56 and a proper mixture is produced because orifice 51 passes a uniform quantity of gas, which is evenly distributed around the orifice 51 because the electrode is well centered by means of set screws 52.

Primary air is drawn at a uniform rate because the pressure differential vbetween the air immediately outside and inside the tube S4-is keptconstant due to the fact that the entire tube 54 liesin a zone of uniform'. pressure. Thus, once the torchis set up for a given type and pressure ofgas, the length ofk the `inlet orifices 56 being set to admit the proper amount ofl primary air, there is no further adjustment required.

The torch, according lto the invention, is suitable for all fuel gases because the amount fed to the torch is controlled through `the control plug 43 and this amount of gas receives the proper amount of primary air through suitable adjustment of the primary air inlet orifices 56.

The electrode 45 will not become bent or otherwise damaged from the radiant heat of the oil burner lbecause said electrode is totally enclosed within `the tube S4 and receives a maximum amount of cooling from the air gas mixture passing along said electrode. Duringthe operation kof? the main burnenthe cold air flowing through 4 the wind box 2 to supply the air for the "combustion of the main burner cools the mixing tube 54vand, therefore, the electrode is fully protected against radiant heat at all times. The insulating sleeve 49 is also well protected against heat in the same way as electrode 45.

Due to the venturi at the orifice S1 where the gas fiows from one pressure to a lower pressure along the electrode surface, a further cooling of said electrode is obtained. v v

While a preferredtembodiment according to the present invention has been illustrated and described it is understood that Vvarious. modifications may be'resorted to without departing from the spirit and scope of the appended claim.

What I claim is:

A fiame igniter comprising a first tube, an electrode extending through said first tube and projecting beyond one end of the latter, an insulating sleeve about said electrode, said first tube `having a flange defining a gas discharge orifice extending around said electrode and said sleeve at said one end of said first tube, means ad justing said electrode and said sleeve with respect to said flange to adjust said orifice, a second tube coaxial with said first tube telescopically movable over said one end of said first tube and completely enclosing said electrode, said second tubebeing provided with air inlets located adjacent and in communication with said orifice of said first tube, a nozzle at the outermost end of said second tube, and means `for adjustingsaid first tube with respect to said second tube to fully open and partially close said air inlets while positioning the electrode in adjusted relationship to the nozzle, said electrode having a tip spaced from the inner surface of said second tube and located within said secondY tube and terminating Yrearwardly of saidno'zzle to form a spark gap.

References Cited in thefile of this patent UNITED l'STATES PATENTS 617,044 Pinkham Jan. 3, 1899 1,557,249 Goodseide Oct. 13, 1925 2,164,417 MtZKee 1- Q'. July 4, 1939 2,402,763 Longini June 25, 1946 2,412,655 Shannon Dec. 17, 1946 2,439,609 Mittendorf Q.- Apr. 13, 1948 2,483,081 Wrigley Sept. 27, 1949 2,616,790 swindin Nov. 14, 1952 l2,627,308 ,Clark Feb. 3, 1953 2,666,480 Peterson .A. Jan. 19, l1,954 

